TV reunions turned into movies can either be great fun or run the risk of making us ask, "What were they thinking?"

Serenity, for example, was a swell 2005 action film featuring the cast of the prematurely canceled Firefly. But 2008's Sex and the City: The Movie (not to mention 2010's Sex and the City 2) was a critical dud. The magic, as least for me, was gone.

But sometimes fans just enjoy seeing their old favorite characters again. What besides nostalgia can excuse the unfortunate Netflix Full House sequel Fuller House? And yet, that series was inexplicably renewed for a two-part third season. Part 2 will stream Dec. 22.

Nonetheless, there are plenty of fans who binge Fuller House and love every episode.

That's how I was with Psych. The wacky buddy comedy/drama starring James Roday and Dule Hill as Shawn Spencer and Burton "Gus" Guster ran on USA from 2006 to 2014. I never missed an episode.

Reruns and syndication on Ion Television, Amazon, Vudu and Apple iTunes have developed a cult following, and the so-called "Psych-O's" will be in tall cotton when Psych: The Movie debuts at 7 p.m. today on USA. That's right -- USA is getting the band back together, and that includes Shawn and Gus and all the rest of the original cast and characters.

USA didn't make preview copies available to those of us who normally get those sorts of things, so I can't give you specifics. However, the film has been heavily advertised on USA and on the website, and that was enough to convince me to tune in.

Here's a reminder of the show's premise.

Childhood friends Shawn and Gus are partners in a detective agency called Psych, with Shawn passing himself off as psychic. Instead of being gifted, Shawn was taught by his detective dad to hone his powers of observation and deduction to such an extent that he seems psychic. He manages to get himself hired as a freelance consultant to the Santa Barbara Police Department.

Hilarity and adventure ensue.

Here's all USA is saying about Psych: The Movie. It's not much.

"The movie picks up in San Francisco three years after the TV series finale. Shawn, Gus and some returning fan-favorites come together during the holidays after a mystery assailant targets one of their own. A comedic thrill ride follows, as the wild and unpredictable Psych team pursues the bad guys, justice ... and food!"

I don't know if the movie will rise to the level of "a comedic thrill ride," but the banter between Shawn and Gus was always some of the most enjoyable on TV.

Creator Steve Franks and Roday wrote the movie together, with Franks directing. Franks has said he hopes to turn Psych into a film franchise and has plans for five additional movies.

• The Crownreturns Friday for Season 2 on Netflix. There are 10 episodes of this marvelous drama, which follows the early years in the reign of Queen Elizabeth II, played with surprising elan by Claire Foy (Wolf Hall), who won a Golden Globe and an Emmy nomination for the role.

If you only know Queen Elizabeth as the matronly nonagenarian who likes Welsh corgis and is trying her best never to die so that Prince Charles cannot become king, then check out this series.

Season 2 will focus on the heavily scrutinized royal marriage.

• Holiday spirit. Get your Yule on tonight with ABC. Shrek the Halls is up first at 7 p.m., followed by Toy Story That Time Forgot at 7:30.

• Sweet dreams. Season 3 of The Great American Baking Show debuts at 8 p.m. today on ABC with cookbook author Ayesha Curry and former NFL star Anthony "Spice" Adams as hosts.